Forecasting surface-layer optical turbulence above the Tibetan Plateau using the WRF model

Abstract

This study investigates the performance of forecasting the surface-layer optical turbulence (Cn2) using the Weather Research and Forecasting (WRF) model. The forecasts are compared with the measurements of two instruments, a large aperture scintillometer and a micro-thermometer. The short- and medium-range WRF-predicted Cn2 vary little under strong turbulence conditions (generally during daytime when strong wind speed and unstable atmosphere occur inside the surface layer), but are relatively divergent for weak turbulence. The predicted Cn2 agree well with the trends of measurements among different forecast times (in most cases the correlation coefficients exceed 0.7), but the short-range forecasting shows slightly better performance than the medium-range forecasting.